The 2006 essay you're referring to in your question is Turning point at Chernobyl and it was widely published across the entire world, it's certainly worth the roughly five or ten minute read and does a fairly good job of answering your first question in and of itself. [1] Gorbachev's explanation of why Chernobyl, as opposed to his own policies of Glasnost' (Openness) and Perestroika (Restructuring), was the true cause of the Soviet Union's downfall can be found towards the end of the essay where he writes the following:
The Chernobyl disaster, more than anything else, opened the possibility of much greater freedom of expression, to the point that the system as we knew it could no longer continue. It made absolutely clear how important it was to continue the policy of glasnost, and I must say that I started to think about time in terms of pre-Chernobyl and post-Chernobyl.
So what is he saying here?
He's saying that the Chernobyl disaster showed that the secretive, bureaucratic machinery that had defined the Soviet model up to then was no longer viable in the modern world where an accident such as the one that occurred on 26 April, 1986 could not only endanger the entire Soviet Union, but indeed, the entirety of human civilization. Gorbachev denies here, and elsewhere, that the Politburo engaged in anything like the coverup of which they were accused by certain western entities. [2]
Chernobyl opened my eyes like nothing else: it showed the horrible consequences of nuclear power, even when used for non-military purposes. One could now imagine much more clearly what might happen if a nuclear bomb exploded. According to scientific experts, one SS-18 rocket could contain 100 Chernobyls.
Gorbachev is and was a genuine and sincere man, but it's quite likely that he is, at the very least, lying by significant omission here-- though as you'll read further on, the accusation has been made much more strongly than that. A 1990 book by Russian journalist Alla Yaroshinskaya called Crime without Punishment revealed a large amount of documentary evidence which showed that the Politburo, as well as numerous other organs of Soviet power, were aware that the disaster was worse than they were letting on-- the only real question is whether or not they were aware just how bad it really was. The justification for their secretiveness was that until there was a contingency plan in place, revealing the true extent of the disaster was not an option. [3] Consider the minutes from an emergency meeting of the Politburo on 4 May, 1986 (eight days after the disaster):
The report of Mr Schtepin [Soviet First Deputy Minister of Health Care] on the hospitalization and medical treatment of the population exposed to radiation. It is noted that by 4 May, a total of 1,882 persons have been hospitalized. The total number examined reached 38,000 persons. 204 persons were diagnosed with radiation syndrome of varying seriousness. These include 64 children. 18 persons are in a critical state. [4]
Compare that to his first public acknowledgement of the disaster on 14 May, 1986 (10 days after the aforementioned Politburo meeting, and 18 days after the disaster) where he claims that nine people died in the explosion, but makes no mention of the 200+ positively diagnosed with radiation poisoning or 18 more in critical condition. When considering that the current figures of deaths directly attributable to Chernobyl is still only around 50 (as if that number is somehow insignificant), according to the World Health Organization, not mentioning the hospitalization of thousands, as well as the then still existent danger of global catastrophe, one has to examine Gorbachev through at least a partially critical lens. [5] A 2006 Greenpeace report estimates the number of cases of radiation-induced cancer deaths directly caused by the Chernobyl disaster to be more than 100,000. [6] (see pp. 15)
I'd personally trust WHO much more than Greenpeace on this issue, but the point is still that nine was a wild, and probably willful, underestimation.
In the last days of the Soviet Union (literally in the same week the hammer and sickle would be lowered over the Kremlin for the final time on 25 December, 1991), a Ukrainian parliamentary commission released a report which damned the Communist Party of the Soviet Union, and Mikhail Gorbachev (among others) personally, of quote:
[A] total lie, falsehoods, cover-up and concealment. [7]
They demanded additional trials at the highest levels of government and made the accusation that the Politburo was fully aware of the extent of the disaster within 12 hours of the explosion at Reactor Number Four, according to documentation presented by the head of the commission Volodymyr Yavorivsky.
So onto your second question, the answer to which will be mercifully short, as it's largely based on any one person's own interpretation of the events. Did the Chernobyl disaster contribute to the collapse of the USSR? Without a doubt. Was it the main cause? I don't think the evidence supports that statement. The bureaucracy coming apart allowed the Soviet Union to be dissolved. Without that, it's hard to imagine that the USSR would have collapsed when and how it did. That bureaucracy came apart because of the changes to the system made by Mikhail Gorbachev which decentralized a large amount of the Soviet power structure and allowed the various subordinate nations to leave the Soviet Union of their own volition. I talk about those changes in this answer, which created the means for the Soviet Union to come apart as a bureaucratic process rather than a traditional revolution. Those means would not have been present without the changes of Glasnost' and Perestroika. Now, I'll indulge a very brief counterfactual-- without Gorbachev's reforms, could Chernobyl have been the primary catalyst of the Soviet Union coming apart? I think that answer is much more likely to be yes, but I'll just leave it at that since it's purely speculative.
So, I have pieced this together from a couple of answers on a similar question I gave eight or nine months ago, and it specifically addresses the question of "Did the Chernobyl disaster contribute to the collapse of the USSR?"
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The Soviet economy was increasingly dependent on oil as the seventies stretched into the eighties. There was no hope of economically catching up to the West, especially on the tails of Afghanistan, the oil crash, the disastrous anti-alcohol campaign, and Chernobyl. When you pair this with the easing of restrictions on travel and access to the Western media -- allowing families to see movies and television shows from the West, read Western publications, and interact with foreigners on a more regular basis, the seeds of socio-economic discontent are being sewn. They could have soldiered through the fall in oil prices by increasing military equipment sales, cutting back of the cost of living, and further restricting what was allowed to be produced en-masse (no more consumer goods, only tractors and missile launchers!) but I feel that would have served to sharpen the divide between USSR and the West that was becoming more apparent with every show episode, movie, and glimpse into the lives of a Western person or family.
According to an IAEA report on Chernobyl located here, cost estimates from a variety of government sources for the Chernobyl accident are in the area of "hundreds of billions of dollars." When calculating costs, the IAEA report looks at: • Direct damage caused by the accident
• Expenditures related to:
• Actions to seal off the reactor and mitigate exclusion zone consequences
• Resettlement of people and the construction of new housing
• Social and health programs for the affected population
• Environmental research, radiation monitoring
• Radio-ecological improvement and disposal of radioactive waste *Indirect losses relating to the opportunity cost of removing agricultural land and forests from use and the closure of agricultural and industrial facilities, and
• Opportunity costs, including the additional costs of energy resulting from the loss of power from the Chernobyl nuclear plant and the cancellation of the Belarus nuclear power program.
Over 3,000 square miles of agricultural land was removed from service in the wake of Chernobyl. An additional 2,700 square miles of forest was restricted from timber production. Another report by the Belarus foreign ministry says that Belarus itself lost 20% of its agricultural lands; 25% of Belorussian forests were contaminated and 132 deposits of mineral resources were further contaminated. I sourced this information here. This isn't taking into effect medical costs, further costs to agriculture from neighboring and associated areas because now people don't want to eat anything that comes from near the area, not just the area itself. Gorbachev can claim that cleaning up the Chernobyl disaster wasn't economically crippling, but there are wide-reaching second and third-order economic effects that can only be placed at the feet of Chernobyl.
Could the Soviet Union have survived the oil crash? Sure. Could it have survived costly adventurism in Afghanistan? Sure. Could it have survived Chernobyl (in an economic sense)? Sure. Were these three events, in addition to other grievous mistakes like the anti-alcohol campaign, too much for the stagnant-or-worse Soviet economy to handle? I think yes. I don't want to pin the dissolution of the USSR on the economics of Chernobyl -- or honestly, the economics of anything. It was a socio-political event informed and flavored by the economics of the time. The Chernobyl disaster was just another stressor on an already over-taxed system. The real culprit here is Chernobyl taking place in an era of burgeoning glasnost', where the government is trying (after a fashion) to deal with this tragedy in a (generally) forthright way. The erosion of trust in the Soviet government in the wake of Chernobyl cannot be discounted, and I think plays a significant role in marching the USSR (as a polity) toward the proverbial gallows.
Stephen Kotkin's Armageddon Averted covers the end of the Soviet Union really well; he suggests that it had a lot to do with economics. If the oil crisis hadn't happened in the late 1970s, the Soviet Union might have become fiscally insolvent, and now the debate would rage about how much credit to give Jimmy Carter for defeating communism. Jimmy Carter! Imagine! But, the oil crisis did happen, and the USSR was particularly well-positioned to take monetary advantage of it and continue limping along into the 1980s.
Chernobyl happened to a society reeling from economic pressure on the heels of an oil crash and a quagmire of an invasion in Afghanistan, while also feeling social pressure radiating from the eastern bloc inwards for more freedom – of speech, of the press, of choice in people’s own lives. It happened to a government with a relatively young leader – Mikhail Gorbachev, 55 years old in 1986 – who was trying to shrug off the Soviet gerontocracy and their secretive, old-Soviet types of attitudes which were choking the life from a system he believed in. Discord and discontent were rampant in the USSR by April 1986. The oil boom that had bolstered the Soviet economy for most of the 1970s and early 1980s had ground to a halt; seemingly overnight, the full coffers from the oil disappeared. Soviet emigres derided the USSR as a land of kleptocracy. The ability of Soviet citizens to view Western television and listen to Western radio served to break the insular hold the Soviet state had on its own citizens and served to show the stark contrasts between citizens of the societies.
David Marples’ first book on the event, Chernobyl and Nuclear Power in the Soviet Union, focused on the background of the disaster and what was known about the Chernobyl event at the time of the book’s publication in 1987. His contention in this first book – one with which I agree wholeheartedly – is that due to the pressure to reform and the influence of glasnost’, the Soviet government released far more information, and were more open and honest in their discussions about Chernobyl than they otherwise would have been (or, in fact, actually had been in the past). By Marples’ second book on the subject, The Social Impact of the Chernobyl Disaster, he has changed his tune, however: Marples suggests that the initial response to the Chernobyl disaster demonstrates a particular absence of glasnost’, the idea that, faced with empirical evidence of something very wrong occurring, the both the central and local Soviet authorities would only admit something part of the way – yes, there was radiation, but it was only slowly rising, so how much of a danger could it be?
There is also something to be said for the idea that, taking Marples’ idea at face value, and that the official, local response did in fact represent a particular lack of glasnost’, there is still the larger governmental response which unfolds in the days, months, and years after the initial thirty-six hours; that on a smaller, local level, those in charge of the plant were falling into old habits of reporting self-serving information to higher without regard to the consequences, where the response changes and morphs into more of a forthright one once the central government – and the rest of the USSR, as well as portions of the world – gets involved.
In short: Chernobyl certainly worked economically and politically to hasten the decay of the Soviet Union. It stretched the finances of the USSR to the extreme, while concurrently working to erode much of the remaining citizen's confidence, due to oftentimes conflicting information being put out in the press about the Chernobyl accident -- information which itself tended to be contradicted by reporting from the Western press (which Soviet citizens had easier access to). The end of the USSR was (probably) nigh, and the Soviet Union almost didn't make it to the Chernobyl disaster. So, to me, it had a role, but it was a role which might have easily been filled by any other disaster coming at the same time and place; or it might have been filled by nothing but the passage of time and the (albeit slower) erosion of the USSR as a power.
Sourcing: Stephen Kotkin, Armageddon Averted Thane Gustafson, Crisis amid Plenty: The Politics of Soviet Energy under Brezhnev and Gorbachev Konstantin M. Simis, USSR--the Corrupt Society: The Secret World of Soviet Capitalism David Marples, Chernobyl and Nuclear Power in the Soviet Union Marples, The Social Impact of the Chernobyl Disaster